In patients with peripheral arterial disease, limitation of exercise capacity will reduce the level of everyday physical activity and affect the quality of life. This study was designed (1) to examine the health-related quality of life of patients with intermittent claudication, and (2) to verify whether treadmill performance is related to the patient's perceived ability to function in the community. In 251 patients with intermittent claudication and 89 matched normal subjects, quality of life was assessed by a general health index questionnaire, the McMaster Health Index Questionnaire (MHIQ), which covers three dimensions of life (physical, social and emotional function). The maximal walking capacity of intermittent claudication patients was measured by the treadmill test. When controls were compared to intermittent claudication patients using the MHIQ, it was found that intermittent claudication patients showed a significant (p < 0.01) impairment of 'general health' and lower scores for physical (0.90 +/- 0.17 vs 0.65 +/- 0.17; p < 0.01), social (0.71 +/- 0.11 vs 0.63 +/- 0.12; p < 0.01) and emotional (0.75 +/- 0.17 vs 0.65 +/- 0.15; p < 0.01) function. Age, gender and work status had a significant impact upon health scores in several areas. Treadmill performance did not correlate with social or emotional function, whereas there was a small but significant relationship between maximal walking capacity and physical function scores (r = 0.197; p < 0.01). This study suggests that impairment in quality of life experience by patients with intermittent claudication poorly correlates with the reduced exercised capacity assessed by the treadmill test. Therefore, the evaluation of medical and surgical treatment of intermittent claudication should include the administration of a questionnaire for quality of life assessment.